causes of over heating

[nc30 madness]

would anyone know the causes of an nc30 over heating, it was running just fine until the other day when i could hear the rad boiling and the over flow under my seat, i have checked that the rad fan is working

please help

[ozracer]

Blocked radiators, low on water, pump not pumping, engine running lean. Look at the simple things first and work your way up.

[CMSMJ1]

faulty rad cap too

these bikes do run very hot....

[nc30 madness]

thanks for such a quick reply guys
it could be my that my bike is running too lean because it was also cutting out easily
i dont understand as i just got my carbs balanced 4 months ago
and how can the carb settings change so fast, what causes carb settings to change

[ozracer]

The engine can run lean if it doesn't get enough fuel. Blocked filter, faulty fuel tap, split in vacuum hose that goes to fuel tap.

[Neosophist]

thanks for such a quick reply guys
it could be my that my bike is running too lean because it was also cutting out easily
i dont understand as i just got my carbs balanced 4 months ago
and how can the carb settings change so fast, what causes carb settings to change

You are mistaking carb balancing for mixture setting.

Having unbalanced carbs will give you a rough idle.. to change the mixture (rich / lean) you have to change the sizes of the jet(s) and / or adjust the pilot screw.

An example of needing larger jets might be putting an aftermarket exhaust can on, changing the air-box setup / air filter.

Carb balancing is supposed to be checked every 8000km if I recall correctly.

If it's been set-up and you havn't changed anything else i'd check the others first.

-Rad cap correct model and sealing ok (it has to hold pressure so even if it looks ok it might not be, a good shop can test this for you

-Water pump working? (if you drain the coolant system you can take the cover off to inspect the blades, and spin the engine over, make sure there all ok and it turns.

-While the coolant is drained run a hosepipe throguh the radiator and engine in both directions to flush out any crap and use correct (silica free, motorcycle anti-freeze) when re-filling it, in a 50/50 ratio.

-Before you do that tho take off the lower rad if it's full of crap and soak it overnight in a bucket of strong de-greaseer (ie tfr etc) and use a LOW pressure hose the next day to wash away all the crap out of it.

-If you have patientce you can buy a radiator ' FIN comb' have a look on ebay, and straighten up all the bent fins... it will help if you have lots :-)